配有螺旋及焊接圆方组合箍的足尺混凝土方柱轴压性能试验研究

为研究螺旋式或焊接式箍筋约束方柱的轴压性能,完成了2根配有绑扎复合箍和4根配有螺旋及焊接圆方组合箍的足尺混凝土方柱的轴心受压试验,测得了试件的极限承载力、轴向变形和箍筋应变,研究了不同箍筋组合形式对足尺混凝土方柱轴心受压承载能力及变形能力的影响,提出方形螺旋式或焊接式箍的间接钢筋面积换算公式. 试验结果表明:螺旋焊接组合箍能一定程度提高足尺混凝土方柱的承载能力,但由于方箍肢距较大,试件后期变形能力与复合箍相比略有下降;轴向荷载作用下,配箍率相同的试件的极限承载力与其箍筋应力值的大小直接相关;高强箍筋可延缓试件承载力下降速率,显著提高试件的变形能力.

Experimental Study on the Axial Compression Performance of Full-scale Reinforced Concrete Column With Spiral and Welding Circular and Square Combined Hoop

To study the axial compression performance of the full-scale square reinforced concrete column with spiral and welding composite hoop, 2 full-scale concrete square columns with binding hoop and 4 full-scale concrete square columns with spiral and welding circular square combination hoop under axial compression test were completed, the ultimate load-carrying capacity, axial deformation and stirrup strain were measured, the effect of different stirrup combination form of bearing capacity and deformation capacity of full-scale axial compressed concrete column were studied, and the indirect reinforcement area conversion formula of square spiral type or welding type hoop was put forward. The test results show that the spiral and welded composite hoop, to a certain extent, can improve the bearing capacity of full-scale concrete square columns, but because of square hoop with big spacing of stirrup legs, compared with the specimen with binding composite hoop, the deformation capacity of the specimen with spiral and welded composite hoop are a little poor at the later stage of the loading. Under axial loads, the bearing capacity of the specimens with same stirrup ratio is directly related to the stirrup stress values. High-strength stirrup can delay the specimen capacity decline rate, and significantly improve the deformation capacity ofthe specimens.